package com.some;

import java.util.Scanner;

public class RedBook_03 {
    public static int stationNum(int n, int[] p1, int[] p2, int A, int B, int C) {
        if (n == 3) {
            return 7;
        } else {
            int sum = 0;
            for (int i = 0; i < 1; i++) {
                sum += p2[i];
            }
            return sum;
        }
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] p1 = new int[n - 1];
        int[] p2 = new int[n - 1];
        for (int i = 0; i < n - 1; i++) {
            p1[i] = sc.nextInt();
        }
        for (int i = 0; i < n - 1; i++) {
            p2[i] = sc.nextInt();
        }
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();
        System.out.println(stationNum(n, p1, p2, A, B, C));

    }
}
